/Engine/Source/Runtime/InteractiveToolsFramework/Public/BaseBehaviors/BehaviorTargetInterfaces.h
The result's bHit property determines whether the mouse wheel action will be captured. (Perhaps the mouse wheel only does something when mousing over some part of a mesh)
hit information at this point
[FInputRayHit](API\Runtime\InteractiveToolsFramework\FInputRayHit) ShouldRespondToMouseWheel ( const [FInputDeviceRay](API\Runtime\InteractiveToolsFramework\FInputDeviceRay) & CurrentPos )